Filter mat holder



Aug. 5, 1958 'A. F. HUBBARD Y 2 FILTER MAT HOLDER FiledDec. 21, 1955 Q QQ %Q /8 Q Q 5 Q Q Q Q Q Q 2 FlG.l

/9 II II E I 0-;15 I FIG.2 [2 E o I6 i FIG. 4

'4 6 INVENTOR.

FIG. 5 ARTHUR EHUBBARD BY MW ATTOR N EY United States Patent FILTER MATHOLDER Arthur F. Hubbard, Moline, Ill., assignor to American Air FilterCompany, Inc., Louisville, Ky., a corporation of Delaware ApplicationDecember 21, 1955, Serial No. 554,551

2 Claims. (Cl. 183-49) The present invention relates to an improvedframe for holding air filter mats.

Filters of the met or pad type are generally held in a vertical plane ina frame provided with a foraminous front cover and a foraminous rearwall, which allow passage of air through the filter pad. The cover, orrear wall of the frame may have horizontal spikes which become imbeddedin the mat when the mat is inserted so as to prevent sagging of the matbut they do not prevent the mat from falling out of the frame, so acover is necessary to keep the filter pad in the frame. In operation,the mat, and the outer face of the cover of the frame become coveredwith lint and dust, and when it becomes necessary to replace or renewthe pad, it is necessary to remove the soiled cover, replace the mat,and then clean the cover before it is replaced. The need to handle andclean the cover is objectionable, but so far as I am aware, the coverhas been considered essential to hold the mat in place.

It is an object of the present invention to provide a coverless filterframe which effectively holds the filter pad in place, thus eliminatingthe cover and its objectionable dirt collecting propensities.

In accordance with the present invention the cover of the filter frameis eliminated, and the filter pad is held against falling out by aplurality of prongs or spikes extending horizontally from the upstreamwall of the frame, the spikes being provided at their free ends withtransverse upwardly directed barbs or hooks. When the filter pad isinserted in the frame, the spikes penetrate the mat, and the barbs holdthe mat against falling out of the frame. The barbed spikes are arrangedto also prevent sagging of the mat.

The spikes may be integrally attached to the downstream wall of theframe, or they may be attached in a manner permitting removal of thebarb or spikes.

The invention will be described in greater detail in the followingspecification taken in connection with the accompanying drawingillustrating preferred embodiments by way of example, and wherein:

Figure 1 is a perspective view of the frame embodying the invention, asviewed from the open side with part of the mat broken away;

Figure 2 is an elevational view of a barbed spike prior to having itsmounting end bent to form a hook;

Figure 3 is a plan view of a barbed spike having its mounting end bentto form a hook;

Figure 4 is a fragmentary view of a modified filter frame;

Figure 5 is a section taken on line VV of Figure 4, and

Figure 6 is a side elevation of Figure 5.

Referring to the drawing, Figure 1, there is shown a filter frame havinga top 1, bottom 2, and two side members 3, 4, forming a rectangle. Theupstream wall 5 may be constructed of expanded metal, or may be formedin any other manner to permit passage of air therethrough, thedownstream end 6 of the frame being open.

2 A filter pad 7 of matted, crossed or interlocked fibers, or filamentsis inserted through the open end 6 of the frame.

The upstream wall 5 has disposed at suitable intervals, a plurality ofspikes, prongs or tines 8, which are pointed or tapered so as topenetrate the filter pad when the pad is inserted into the frame. Theform of spike illustrated, and shown in detail in Figs. 2 and 3 is madefrom a flat strip or ribbon of metal 9 tapered at its end 10, and provided with an upwardly directed transverse barb 11. This spike isattached to the upstream wall 5 by bending or folding the end 12 aroundthe metal web of the expanded metal wall and crimping or folding themetal at 13 around the web to hold the spike in place. The spike ispositioned so the barb is directed upwardly. A plurality of such barbedspikes are suitably arranged on the upstream wall of the frame.

In operation, when a filter pad is inserted in the frame the taperedprongs 10 penetrate the filter pad and the barbs 11 hold the pad inplace so that it cannot fall out of place. That is, the function of thebarbed spikes is to prevent the filter pad accidentally falling out ofplace, and incidentally, to prevent sagging of the pad.

To replace the dust loaded filter pad, the pad is lifted slightly todisengage the barbs, and is then drawn through the open end of theframe. Removal of the pad does not entail removal of any cover, as nocover is employed. A clean filter pad now is loaded into the open end bypushing it onto the barbs, and the loaded filter frame is inserted intothe filter. It will be seen that the barbed spikes replace or eliminatethe cover, so that replacement of a filter pad does not involve handlingor cleaning a dirty cover.

In the modification shown in Figs. 4 to 6, the downstream end of thefilter frame is provided with spaced bars or channels 14, which allowsair to fiow through the frame, and to these bars are welded at suitablepositions the barbed prongs 15. The barb on the prong is formed bybending the free end of a rod into the form of a hook at 16, andsharpening the hook.

I claim as my invention:

1. A holder for a filamentous air filter mat comprising an open endedperimetric frame member of substantially U -shaped cross section and ofa depth sufficient to peripherally enclose a filamentous filter mat ofpredetermined thickness insertable therewithin, an air pervious backingscreen mounted in one open end of said frame member, and a plurality ofselectively disposed barbed end prong members removably mounted on saidbacking screen and having the barbed ends thereof extending into thespace defined by said frame member whereby a filter mat inserted intosaid frame member and into abutting relation with said backing screen isperipherally supported and retained by said frame member and selectivelysupported and retained at locations remote from said frame member by theembedded engagement of the barbed ends of said prong members therewith.

2. A holder for a filamentous air filter mat comprising an open endedperimetric frame member of a depth sufiicient to peripherally enclose afilamentous filter mat of predetermined thickness insertabletherewithin, an air pervious backing screen having intersecting webportions mounted in one open end of said frame member, a plurality ofprong members each removably secured at one end thereof to saidintersecting web portions of said backing screen and having the otherends thereof projecting into the pad receiving space defined by saidframe member and barbed means on said last mentioned ends of said prongmembers whereby a filter mat inserted into said frame member through theopen end thereof and into abutting relation with said backing member isselectively Patented Aug. 5, 1958 thereon.

References Cited inthe file of this patrit UNITED STATES PATENTS Slayteret a1. May 30, 1939 Belsher Sept. 24, 1946 Davis Apr. 25, 1950 PalmerJuly 24, 1951 Shapirov Aug. 26, 1952 Rowe May 5, 1953 Lindner Oct. 4,1955

